<!DOCTYPE html>
<html>
<head>

</head>
<body>
<script type="text/javascript">
    var Sys = {};
    var ua = navigator.userAgent.toLowerCase();
    if (window.ActiveXObject)
        Sys.ie = ua.match(/msie ([\d.]+)/)[1]
    else if (document.getBoxObjectFor)
        Sys.firefox = ua.match(/firefox\/([\d.]+)/)[1]
    else if (window.MessageEvent && !document.getBoxObjectFor)
        Sys.chrome = ua.match(/chrome\/([\d.]+)/)[1]
    else if (window.opera)
        Sys.opera = ua.match(/opera.([\d.]+)/)[1]
    else if (window.openDatabase)
        Sys.safari = ua.match(/version\/([\d.]+)/)[1];

    //以下进行测试
    if (Sys.ie) document.write('IE: ' + Sys.ie);
    if (Sys.firefox) document.write('Firefox: ' + Sys.firefox);
    if (Sys.chrome) document.write('Chrome: ' + Sys.chrome);
    if (Sys.opera) document.write('Opera: ' + Sys.opera);
    if (Sys.safari) document.write('Safari: ' + Sys.safari);
</script>
</body>
</html>